Long-time behaviour of quantized distributions in forward–backward semiclassical dynamics

The paper reports investigations of the characteristics of phase space distributions in forward–backward semiclassical dynamics (FBSD) calculations. By virtue of Liouville’s theorem and energy conservation, the volume of the negative regions is rigorously conserved and the energy distribution is invariant during time evolution. Thus, while the phase space density is not invariant under FBSD, exhibiting a weak time dependence mostly in its wings, it retains its quantum mechanical characteristics and does not revert to a classical Boltzmann distribution at long times. Illustrative applications on liquid neon near its triple point are presented.